What You Need To Know About Electrical Test Equipment Used On Low Voltage Systems

According to the Electricity at Work Regulations 1989, those in control of part or all of an electrical system must ensure it is safe to use and maintained in a suitable condition.

To this end, the Health and Safety Executive (HSE) has published a guidance note entitled Electrical test equipment for use on low voltage electrical systems GS38 Fourth Edition, which contains information on how to comply with the law.

But Instrotech, an authorised distributor of electrical test equipment for use by electricians, has come up with a summary of what you need to know about test probes, clips and leads, sockets and terminals, and voltage detectors.

Along with conforming to the requirements of BS EN 61010-031 (and BS EN 61243-3 in the case of 2-pole voltage detectors), modern test probes must be marked with the rated insulation category and the manufacturing’s name or identifying mark.

Probes and clips must also:

Have finger barriers or be shaped to guard hand contact with live conductors

Be insulated to leave an exposed metal tip no longer than 4mm across any of its surface

Have suitable high-breaking capacity when used alongside a multimeter

Whereas leads must:

Be adequately insulated and sheathed to protect against mechanical damage

Be flexible and of sufficient capacity but also long enough for purpose

Be coloured so one can be easily distinguished from the other

Not have accessible exposed conductors other than the probe tips

Sockets and terminals

The biggest risk from sockets and terminals is inadvertent hand or finger contact with any live conductor, so steps must be taken to reduce this danger.

What’s more, the terminals and sockets of test equipment may also require shrouding in accordance with the category. However, test leads and equipment that already conform to BS EN 61010 or BS EN 61243-3 will meet this requirement anyway.

Voltage detectors

Electrical test equipment used only for detecting voltage falls into two categories:

Voltage detectors that rely on an illuminated indication (such as a test lamp) or a scale (like a multimeter). These detectors require protection against excess current, which may be provided by a suitable high-breaking capacity fuse, a low current rating, or by means of a current-limiting resistor. These protective devices are housed in the probes themselves, while the test leads are held captive and sealed into the body of the voltage detector.

Voltage detectors that use two or more independent indicating systems (one of which may be audible) and limit energy input to the detector by the circuitry used. One example is a 2-pole voltage detector, which features an integral test probe, an interconnecting lead and a second test probe. These detectors may be designed to limit the current flowing into the detector and provided with inbuilt test features to check functioning before and after use.

However, single-pole non-contact live-circuit detectors or “voltage sticks” should only be used for identifying live equipment, not for proving it is dead.

For more information on electrical test equipment for use by electricians, read the full guidance note or contact Instrotech today.